Moxifloxacin - A review of its clinical potential in the management of community-acquired respiratory tract infections

Moxifloxacin is an extended-spectrum fluoroquinolone which has improved cov erage against gram-positive cocci and atypical pathogens compared with olde r fluoroquinolone agents, while retaining good activity against Gram-negati ve bacteria. The antibacterial spectrum of moxifloxacin includes all major upper and lower respiratory tract pathogens; it is one of the most active f luoroquinolones against pneumococci, including penicillin- and macrolide-re sistant strains. In in vitro studies, emergence of bacterial resistance was less common with moxifloxacin than with some other fluoroquinolones, but t his requires confirmation in large-scale clinical studies. As with other fluoroquinolones, moxifloxacin achieves good penetration into respiratory tissues and fluids. It shows a low potential for drug interact ions and dosage adjustment is not required for patients of advanced age or those with renal or mild hepatic impairment. The efficacy of oral moxifloxacin has been demonstrated in large, well-desi gned clinical trials in patients with community-acquired pneumonia, acute e xacerbations of chronic bronchitis or acute sinusitis. Moxifloxacin 400mg o nce daily achieved bacteriological and clinical success rates approximately 90% or higher. It was as effective as, or more effective than, comparators including clarithromycin, cefuroxime axetil and high dose amoxicillin in t hese trials. The most commonly reported adverse events in patients receiving moxifloxaci n are gastrointestinal disturbances. Moxifloxacin is also associated with Q Tc prolongation in some patients; there are, as yet, no data concerning the possible clinical sequelae of this effect in high-risk patients. Moxifloxa cin has a low propensity for causing phototoxic reactions relative to other fluoroquinolones, and animal data suggest that it has a low potential for causing excitatory CNS and hepatotoxic effects. Conclusions: As an extended-spectrum fluoroquinolone, moxifloxacin offers t he benefits of excellent activity against pneumococci, once daily administr ation and a low propensity for drug interactions. Although studies are need ed regarding its tolerability in at-risk patients with QT interval prolonga tion, available data suggest that moxifloxacin is likely to become a first- line therapy option for the treatment of community-acquired lower respirato ry tract infections, particularly in areas where drug-resistant S. pneumoni ae or H. influenzae are common.